In some wireless communication networks, dynamic adaptive streaming over hypertext transfer protocol (DASH) streaming format is used to deliver media content, such as video, audio, multimedia, and/or other content to a user equipment (UE) over a wireless communication network. DASH has been standardized in Third Generation Partnership Project (3GPP) TS 26.247 V. 10.2.0 as well as ISO/IEC DIS 23009-1 in MPEG. The media content is typically accessed by the UE via unicast HTTP signaling between the UE and a remote HTTP media server that stores the media content. The UE sends an HTTP request that is routed to the remote HTTP media server, and the remote HTTP media server transmits the requested media content to the UE via HTTP in response. This may create high signaling overhead in the network and add delay to the distribution of the media content.
In DASH, a media presentation description (MPD) metadata file provides information on the structure and different versions of the media content representations stored in the server (including different bitrates, frame rates, resolutions, codec types, etc.). In addition, DASH also specifies the segment formats, e.g., includes information on the initialization and media segments for a media player (the media player looks at initialization segment to understand container format and media timing info) to ensure mapping of segments into a media presentation timeline for switching and synchronous presentation with other representations. Based on this MPD metadata information that describes the relation of the segments and how they form a media presentation, clients may request the segments using HTTP GET or partial GET methods.
Multimedia Broadcast Multicast Services (MBMS) specified in 3GPP TS 26.346 is a point-to-multipoint system utilized on cellular networks operating in accordance with one of the cellular standards promulgated by the 3GPP. It is designed for efficient delivery of popular content to many receivers based on broadcast and multicast techniques and was first introduced in release six of the 3GPP Universal Mobile Telecommunications System (UMTS) specification as an optional feature. MBMS was further optimized in the later 3GPP releases based on several enhancements such as multicast broadcast single frequency network (MBSFN) functionality. At the service layer, MBMS also defines delivery protocols for both streaming of multimedia content and reliable download of files, based on the transport-layer protocol based on the user datagram protocol (UDP), using real-time transmission protocol (RTP) for streaming and File Delivery over Unidirectional Transport (FLUTE) for file delivery. MBMS has been adopted as the enhanced MBMS (eMBMS) mode in 3GPP-based Long Term Evolution (LTE) standards development corresponding to 3GPP releases eight and onwards.
DASH-formatted content could be delivered to the UE using both MBMS download delivery methods and/or HTTP-based delivery methods. MBMS-based DASH delivery option may not be available in some service areas, in which case those services might be alternatively provided via unicast. In case of DASH-formatted content delivery over MBMS, FLUTE transport protocol may be used. FLUTE as defined in RFC3926 permits to deliver DASH segments over MBMS such that the client observes them being delivered over HTTP/TCP. HTTP-URL is assigned to each delivered object in FLUTE and the HTTP-URL maps the Segment URLs in the MPD. The UE would identify the received DASH representations based on the comparison of the HTTP URLs contained in the MPD and the URL information included in the FLUTE packets.